Refrigerant sight glass

ABSTRACT

A generally cylindrical centrally bored housing is coaxially secured at one end portion within a short length of copper tubing. The other end of the copper tubing is contoured for connection with a fluid containing line. A tubular core, having a transparent disk closing its bore adjacent one end portion and a line piercing tip formed on its other end portion and having an overall length slightly less than the combined length of the housing and copper tubing, is coaxially received by the bore of the housing. A cap, removably engaged threadedly with the free end of the housing, forces the line piercing tip into the line and seals the core with the housing and the line.

[ Aug. 14, 1973 United States Patent 1191 Mullins REFRIGERANT SIGHTGLASS ABSTRACT A generally cylindrical centrally bored housing is coaxamm i ua QY m we 3.13 e mu Rm. r K w n .n me z maO mxR E E 1 P Wm a m PAA4 2 5 0 2 w m n Pk 0 M n M ml W m BM M 9 JONI m N m d1 w m w h FA m N H7 22 ially secured at one end portion within a short length [52] US.137/559, 62/125, 116/117 C, of pp tubing. The other end of the pp tubing6k 43/00 G0 v is contoured for connection with a fluid containing line.

51 Int. (:1. [58] Field of 73/323, 73;. g gzg f gg i g gxz i zgg gigg$223332: 116/117 R, 117 0; 62/125, 294; 137/559, 318

formed on its other end portion and having an overall length slightlyless than the combined length of the housing and copper tubing, iscoaxially received by the Chatlos...'..... 2/1932 Carroll et al. 7/196473/73,X 62/125 62/294 X 3 Claims, 3 Drawing Figures Jones 12/1970Merwitz, Sr. l2/l950 Chase wmwwmlwnna Patented Aug. 14, 1973 3,752,185

REFRIGERANT SIGHT GLASS CROSS REFERENCE TO RELATED APPLICATION Thepresent invention is an improvement over my copending application Ser.No. 137,376 filed Apr. 26, I971 for Copper Tubing Service Valve.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to refrigerant lines and more particularly to arefrigerant line tapping sight glass.

In order to maintain a refrigerant system operable it is necessary thatthe refrigerant gas containing lines be maintained full of therefrigerant gas. An insufficient quantity of gas contained by therefrigerant lines may occur as the result of a leak in thesystem or aninsufficient evacuation of the lines after performing repairs to thesystem and recharging the lines. An insufficient quantity of gas withinthe refrigerant lines results in malfunction or at least insufficientcooling characteristics, therefore, it is necessary that some means beprovided for determining whether or not the refrigerant lines are fullof refrigerant gas during operation of the system.

This invention is distinctive over my above referred to application byproviding a sight glass within the bore of a line piercing corecommunicating with a refrigerant line to provide visual indication ofthe quantity of refrigerant gas contained by the line.

2. Description of the Prior Art Sight glasses conventionally used inrefrigerant systems generally comprise an elongated fitting havingthreads at its respective ends permitting the fitting to be interposedbetween adjacent ends of a refrigerant line and connected forcommunication therewith. The fitting is provided with a lateral openingclosed by a transparent member for visual indication of 'the quantity ofgas contained by the line. This type of sight glass is generallysatisfactory when installed during assembly of the refrigeratingcomponents, however, many refrigerating systems presently in use are notequipped with a sight glass. When installing a sight glass of the aboveconventional type it is necessary to remove or bleed off the refrigerantgas in order to part a line and install the sight glass therein, thusnecessitating recharging the system after installing the sight glass.

This invention provides a housing and means for its connection with arefrigerant line, intermediate the line ends including a sight glassequipped core for piercing the line and sealing therewith thuseliminating any disassembly or loss of the refrigerant gas and effectinga saving of materials and time.

SUMMARY OF THE INVENTION A generally cylindrical centrally bored housinghaving external threads at one end portion is coaxially connected at itsother end portion with one end portion of a relatively short length ofcopper tubing.

The other end of the copper tubing is contoured to form an arcuaterecess complemental with the radius of a line to be tapped and partiallysurrounds a wall portion of the line for connecting the copper tubing tothe line, as by soldering. A cylindrical core, having a line piercingtip at one end portion and an overall length slightly greater than thespacing between the free end of the housing and the inner surface of thewall of the line to be tapped, when connectedwith thecopper tub ing, iscoaxially received. by the housing. The. end ofthe core, opposite itsline piercing tip, receives a disk-like section of transparent materialin sealingrelation. The. core is moved longitudinally into thehousing'by a cap. threadedly engaged with the housing which forcestheline piercing tip through the wall of the line: to seal. therewithand crimps athin wall free end portion of the housing inwardly inoverlapping, lockingand sealing. relation against the adjacent outerwall surface. of the core.

The principal object of this invention is to provide a sight glassequipped fitting which may be easily connected for communication withthe bore of a. refrigerant gas conducting line intermediate its ends.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective viewof the sight glass components and a fragment of a refrigerant line;

FIG. 2 is a side elevational view of the device when installed on arefrigerant line; and,

FIG. 3 is a vertical cross-sectional view taken substantially along theline 33 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Like characters of referencedesignate like parts in those figures of the drawings in which theyoccur.

In the drawings:

The reference numeral 10 indicates the device, as a whole, comprising ahousing 12 secured to a connector 14 in turn mounted on a line 16 to betapped. The housing 12 is generally cylindrical having a bore 17, and acounterbore 18, forming an annular shoulder 19. The housing has ahexagonal head 20 forming wrench flats intermediate its ends. One endportion of the housing is externally threaded, as at 22. This endportion of the housing is characterized by a reduced periphery forming arelatively thin wall 24 extending coaxially outward from the threads 22for the purposes presently explained.

The other end portion of the housing, opposite the threads 22, isdiametrically reduced and is coaxially received within one end portionof the tubular connector 14 and is secured thereto, as by brazing, toform a gas and fluid tight joint. The connector 14 is preferably formedof the same material and wall thickness as the line 16 to be tapped.

As mentioned hereinabove the line 16 usually comprises a length ofcopper tubing and in this event the connector 14 is similarly formedfrom a length of copper tubing usually diametrically slightly greaterthan the outside diameter of the line 16 for the purposes presentlyapparent.

The other end portion of the connector 14, opposite the housingconnected end, is bifurcated by forming a transverse substantiallyU-shaped recess or slot through its wall end portion defining opposingconnectorlegs 26 and an arcuate bight portion or surface 28 forcontacting a peripheral portion of the line 16. The length of the legs26, when straddling the line 26, is preferably such that their free endsurface projects beyond a diametric line taken through the line 16normal to the axis of the housing bore thus permitting the free endportion of the legs to be bent or crimped inwardly toward each other inline contacting relation in a partial wrap around action on the line 16thus temporarily positioning the connector 14 on the line. The connector14 is then secured to the line, as by soldering, which is easilyaccomplished for the reason that the connector 14 and line 16, beingformed of the same material and substantially the same wall thickness,are easily heated to a soldering temperature.

A step diametered tubular core 30, preferably formed of case hardenedmetallic material, is coaxially received by the housing. One end portion31 of the core is longitudinally and diametrically substantially equalwith the housing counterbore 18. The other end portion of the core isdiametrically reduced, as at 32, for entering the housing bore 17 andforming an annular shoulder '34 for engaging the housing shoulder 19.The free end of the core end portion 32 is integrally connectedcoaxially with a dimetrically reduced centrally bored line piercing tip36 coverging toward its free end and having a beveled end surface 38 forenhancing its line piercing characteristics. The overall length of thecore, and including its tip 36, is slightly greater than the spacingbetween the free end of the housing wall 24 and adjacent surface of theline 16 so that the core may be substantially completely enclosed by thehousing with its cutting tip entering the line 16 in the mannerpresently explained.

The periphery of the free end portion of the core opposite the tip 36 isdiametrically reduced to form an annular shoulder 40. The core iscounterbored and threaded, as at 42, from its end opposite the tip 36and is provided, at the inward limit of the threads 42, with an annular,part circular in cross section, recess for receiving a first seal suchas an O-ring 44.

A cylindrical or disk-like member 46, formed of transparent material, iscoaxially received by the threaded bore of the core and seats in sealingrelation against the first O-ring 44.

A centrally bored externally threaded ring or plate 48 is threadedlyengaged with the core threads 42 outwardly of the disk 46. The plate 48is provided with means to facilitate its insertion and removal such asby broaching its central aperture to form a hexagonal opening 49 forreceiving a conventional set screw wrench, not shown. A second seal orO-ring 50 is interposed between the disk 46 and plate 48 to insuresealing the disk 46 with the wall forming the bore of the core.

An internally threaded cap 52 threadedly engages the housing threads 22and forces the core 30 toward and into the line 16. The cap 52 ischaracterized by a converging wall surface 54 defining its inner closedend, inwardly of its threads, wherein this surface 54 forces the housingthin wall end 24 toward and against the circumferentially reduced endportion of the core 30 outwardly of its shoulder 40 in a crimping andsealing action of the wall 24 for holding the core in place.

OPERATION In operation the housing 12 is connected with the connector14, as described hereinabove, at the time of manufacture. The glassequipped core 30 and cap 52 are supplied to the refrigerant servicepersonnel with the assembled housing 12 and connector 14. The servicemanplaces the connector 14 in straddling relation upon the .line 16 to betapped and makes a soldered connection as described hereinabove.

It should be noted that this soldered connection between the connector14 and line 16 need not necessarily be fluid tight for the reasonspresently explained, however, the soldered joint between the connector14 and line 16 must be sufficiently strong to permit withstanding theline piercing action as described hereinbelow.

The core 30, having the glass or disk 46 installed therein, islongitudinally inserted into the housing with the core tip 36 disposedtoward the surface of the line 16. The cap 52 is then manually engagedthreadedly with the housing threads 22. A pair of suitable wrenches, notshown, are placed respectively, on the housing head 20 and periphery ofthe cap 52 for continuing the threaded engagement of the cap 52 with thehousing wherein, as the cap is progressively moved toward the housinghead 20, the beveled inner surface 54 of the cap, contacting the wallend surface at the threaded end portion of the core, progressivelyforces its tip 36 through the wall of the line 16 in a piercing andsealing action. When the wall of the threaded end of the core issubstantially coextensive with the housing wall 24 the beveled innersurface 54 of the cap simultaneously contacts the free end portion ofthe housing wall 24 and forces it inwardly in crimping and sealingrelation with respect to the reduced end portion of the core walloutwardly of its annular shoulder 40. Since the material forming thecore 30 is preferably formed of relatively hard material, such as steel,its tip 36 forms a gas and liquid tight seal where it pierces the wallof the line 16 and further the thin wall 24 of the housing forms asecondary seal'around the periphery of the core at its threaded end.Axial movement of the core 30 into the housing is limited by the coreshoulder 34 contacting the housing shoulder 19. The bore of the core 30is now in communication with the bore of the line 16. Any air trapped inthe line 16 and collecting within the bore of the core 30 may bereleased by unscrewing the plate 48 a thread or two so that theimpinging sealing action of the O-rings 44 and with the disk 46 isreleased thus releasing the trapped air. The plate 48 is thenretightened to seal the bore of the core.

Obviously the connector 14 may connect the sight glass to a linediametrically equal with or greater than the diameter of the connector.In this event the end of the connector opposite the housing is simplyrecessed or contoured to form an arcuate surface complemental with theoutside radius of the line to be tapped and terminating toward opposingside surfaces of the line in an arcuate curve, as indicated by thedotted line (FIG. 2).

Obviously the invention is susceptible to changes or alterations withoutdefeating its practicability, therefore, I do not wish to be confined tothe preferred embodiment shown in the drawings and described herein.

1 claim:

1. A sight glass for a tubular line, comprising:

a generally cylindrical centrally bored housing having a diametricallyreduced periphery at one end portion forming a relatively thin wall,said housing having external threads intermediate its ends; a tubularmember coaxially secured, at one end portion, to the end portion of saidhousing opposite said thin wall, the other end portion of said tubularmember being transversely recessed to define an arcuate surface formedon a radius complemental with the outside radius of the tubular line tobe tapped,

said tubular member having a wall thickness substantially equal withrespect to the wall thickness of the tubular line to be tapped; atubular core, having a length slightly greater than the spacing betweenthe end of said thin wall portion of said housing and the periphery ofthe tubular line nested by the arcuate surface, coaxially received bythe central bore of the housing, said core having a diametricallyreduced tapered end portion converging toward the tubular line to betapped,

said tapered endportion terminating in a beveled end surface forming theline piercing tip,

said core having a diametrically reduced peripheral end portion of saidcore opposite said line piercing tip is internally threaded and providedwith an annular shoulder adjacent the inward limit of the threads andportion adjacent its end opposite said line piercing tip forming anannular shoulder adjacent the housing thin wall portion;

a transparent disk transversely intersecting the bore said sealing meansincludes:

a centrally apertured plate threadedly received by the core and forcingsaid transparent disk toward said inner shoulder; and,

a resilient seal interposed between said transparent disk and said innershoulder.

3. The sight glass according to claim 2 in which the wall forming thebore of said housing is provided with an annular shoulder facing towardsaid housing thin wall and said core is provided with an outer annularshoulder facing toward said line piercing tip for engaging the housingshoulder and limiting the depth of penetration of said line piercing tipinto the line secured to said tubular member.

1. A sight glass for a tubular line, comprising: a generally cylindricalcentrally bored housing having a diametrically reduced periphery at oneend portion forming a relatively thin wall, said housing having externalthreads intermediate its ends; a tubular member coaxially secured, atone end portion, to the end portion of said housing opposite said thinwall, the other end portion of said tubular member being transverselyrecessed to define an arcuate surface formed on a radius complementalwith the outside radius of the tubular line to be tapped, said tubularmember having a wall thickness substantially equal with respect to thewall thickness of the tubular line to be tapped; a tubular core, havinga length slightly greater than the spacing between the end of said thinwall portion of said housing and the periphery of the tubular linenested by the arcuate surface, coaxially received by the central bore ofthe housing, said core having a diametrically reduced tapered endportion converging toward the tubular line to be tapped, said taperedend portion terminating in a beveled end surface forming the linepiercing tip, said core having a diametrically reduced peripheralportion adjacent its end opposite said line piercing tip forming anannular shoulder adjacent the housing thin wall portion; a transparentdisk transversely intersecting the bore of said core in its end portionopposite said line piercing tip; ring means sealing said transparentdisk with the inner wall surface of said core; and, a cap engaging theexternal threads on said housing, said cap having a beveled inner endsurface for contacting the adjacent outwardly disposed end surface ofsaid core and forcing the line piercing tip of said core into thetubular line to be tapped and subsequently contacting the outer endsurface of said housing thin wall portion and forcing the latterinwardly against the outer surface of said core outwardly of saidannular core shoulder in locking relation as said cap in progressivelyeNgaged threadedly with said housing.
 2. The sight glass according toclaim 1 in which the end portion of said core opposite said linepiercing tip is internally threaded and provided with an annularshoulder adjacent the inward limit of the threads and said sealing meansincludes: a centrally apertured plate threadedly received by the coreand forcing said transparent disk toward said inner shoulder; and, aresilient seal interposed between said transparent disk and said innershoulder.
 3. The sight glass according to claim 2 in which the wallforming the bore of said housing is provided with an annular shoulderfacing toward said housing thin wall and said core is provided with anouter annular shoulder facing toward said line piercing tip for engagingthe housing shoulder and limiting the depth of penetration of said linepiercing tip into the line secured to said tubular member.